Synthesis of Benzo[c][2,7]naphthyridinones and Benzo[c][2,6]naphthyridinones via Ruthenium-Catalyzed [2+2+2] Cycloaddition between 1,7-Diynes and Cyanamides

Photoinduced radical tandem annulation of 1,7-diynes: an approach for divergent assembly of functionalized quinolin-2(1H)-ones

The first photocatalytic trichloromethyl radical-triggered annulative reactions of amide-linked 1,7-diynes with polyhalomethanes were established for the flexible assembly of functionalized quinolin-2(1H)-ones with generally acceptable yields. With the installation of the aryl group (R1) into the alkynyl moiety, C-center radical-initiated Kharasch-type addition/nucleophilic substitution/elimination cascade to produce quinolin-2(1H)-ones-incorporating gem-dihaloalkene, whereas three examples of polyhalogenated quinolin-2(1H)-ones were afforded when amide-linked 1,7-diynes bearing two terminal alkyne units were subjected to BrCX3 by exploiting dry acetonitrile as a solvent.

Rapid assembly of structurally diverse cyanamides and disulfanes via base-mediated aminoalkylation of aryl thiourea

A general method for the preparation of cyanamides and disulfanes from aryl thiourea and halide through a base-mediated strategy is described. Mercaptan and N-aryl cyanamide are the key intermediates in the reaction. The current method is convenient, eco-friendly, and has high yields for the synthesis of substituted cyanamide and functional disulfanes in a one-pot procedure from readily available starting materials.

Synthesis of 5H-chromeno[3,4-c]pyridine derivatives through ruthenium-catalyzed [2 + 2 + 2] cycloaddition

Efficient access to 5H-chromeno[3,4-c]pyridines using Ru-catalyzed [2 + 2 + 2] cycloaddition of α,ω-diynes with cyanamides was developed, providing valuable tricyclic pyridine building blocks and enabling access to a biologically relevant intermediate.

The Renaissance of Organo Nitriles in Organic Synthesis

In the arena of functional group-oriented organic synthesis, the nitrile or cyano functionality is of immense importance. The presence of nucleophilic N -atom, π-coordinating ability of the triple bond, and electrophilic C-center imparts unique and interesting reactivity. Owing to the ability of the nitrile to transform into various other functional groups or intermediates, the chemistry is very rich and diverse. In particular, the involvement of nitrile in numerous organic reactions such as inter- or intramolecular alkyne insertion, [2 + 2 + 2] cycloaddition with alkynes, [3 + 2] cycloaddition with azides, [4 + 2] cycloaddition with diene allow the synthesis of many important carbocycles and heterocycles. Furthermore, the nitrile serves as a directing group in many C-H bond functionalization reactions to introduce diverse functionality and participate as a radical acceptor in radical cascade strategies to obtain a large variety of functional molecules. This review mainly focuses on the reactivity and diverse synthetic application of the nitrile including C-H bond functionalization, alkyne insertion, cycloaddition, and thermal or photochemical cascade strategy. The objective of the current review aims at bringing out the striking collection of various nitrile-triggered organic transformations.